1. Field of the Invention
The invention relates to a tractor-drawn agricultural implement adapted to extract and shred stalks and roots of plants growing in parallel rows, more particularly cotton plants.
In order to prepare the soil, after harvesting, for the new sowing season it is necessary to extract the remaining stalks and roots which are either left on the ground for subsequent gathering, or are shredded into small particles and dispersed over the field as fertilizer. Different kinds of equipment are being used for this purpose, the implements being generally adapted for attachment to an agricultural tractor, both for the purpose of trailing them across the field to be cleaned, and of obtaining the power necessary for extracting and/or shredding the plants. These machines which, in addition to extracting, also shred the stalks have the main drawback that shredding is done rather roughly and irregularly into smaller and larger particles, for the reason that--in the existing machines--the material is not properly fed into the shredding device and that the cuts are, therefor, of a random nature.
2. Objects and Summary of the Invention
Since a market exists for finely comminuted plant material, especially cotton plants, as chickenfeed or as fertilizer, it is the foremost object of the present invention to provide an implement that will extract the roots and stalks and finely comminute them into particles of more or less uniform size. It is a further object of the invention to provide means for gathering the particles in suitable container means for storage and/or transport to other destinations.
The stalk extracting and shredding equipment, in accordance with the invention, utilizes a known extraction method by means of several pairs of obliquely mounted wheels with wide tires which are pressed together and driven in opposite sense of rotation. While equipment travels over and along parallel rows of plants, each plant is gripped between one pair of tires and pulled out of the ground. Whereas in the known kind of equipment the extracted material is left to rot on the ground, or to be gathered by other equipment, the present implement is provided with conveying means which are to grip the stalk immediately after its emergence from between the pair of tires and to feed it into a shredding device adapted to cut it up into small particles. The shredding device is enclosed and attached to the suction opening of a centrifugal blower which will gather the particles and convey them to a closed container or, alternatively, blow and distribute them across the cleared field.
A stalk-extracting and shredding implement, according to the invention, comprises a vehicle frame mounted on wheels and provided with means for attaching it to the rear of an agricultural tractor; the frame carries in its rear portion a blower unit and a rotary shredder of known design, both being driven from the power-take-off of the tractor, and a casing totally enclosing the rotary shredder except for a plant inlet opening and an outlet opening connected to the blower unit. Two arms are pivotally connected to the top of the implement frame above the rotary shredder and extend in oblique downward direction towards the tractor rear, each arm carrying at its lower end two obliquely positioned extractor wheels of known design which are provided with resilient tires having their adjoining surfaces pressed together and are mounted on parallel shafts rotatingly fastened to the arm and driven by hydraulic motors. The implement is characterized by the provision of conveying means, serving to convey the extracted plants from between the tired extractor wheels to the rotary shredder, which comprise a belt conveyor mounted on each of the pivoted arms and consisting of two parallel belt drives having their respective upwardly moving stretches pressed together over a length extending from the extractor wheels to the top of the pivoted arm. The conveying means further comprise two superposed pairs of horizontal feed rollers, positioned in the space between the upper outlets from both belt conveyors and the opening in the casing enclosing the rotary shredder, the sense of rotation of the feed rollers being so directed as to convey extracted plants from the two belt conveyors into the shredder through the opening in the casing.
The belt conveyor on each arm comprises two belts of different lengths lying in a common plane, the shorter of the two belts being proximate to the interveing space between the two arms, each belt is tensioned between a lower driving pulley mounted on the rotatable shaft of the respective extractor wheel and an upper, loose pulley mounted in the upper arm portion, whereby the loose pulley of the longer belt, or the second upper pulley, is positioned at a greater distance from the driving pulley, or the second lower pulley, than that of the shorter belt. The upwardly moving stretches of the belts are urged into close contact by two sets of tension pulleys positioned along these stretches.
In a preferred embodiment of the belt conveyor the loose pulley, or the second upper pulley, of the longer belt is positioned close to the loose pulley, or the first upper of the shorter belt substantially in the axis of the shorter belt drive, which results in delivery of the extracted plants clamped between the contacting belt portions, towards the gap between the arms into the feed roller means. In another embodiment of the belt conveyor the loose pulley of the shorter belt drive is rigidly attached to a rotatable shaft, and coaxially with this pulley a sprocket wheel is similarly attached to this shaft, adapted to be rotated together with the loose pulley. About a quarter of the circumference of the sprocket wheel is enclosed by a curved guide extending from the point where the contact between the two belt ends to a point above the feed roller means.
The feed roller means comprise two pairs of parallel rollers in close proximity driven in opposite sense of rotation, so positioned that their vector of movement of their contacting surface--and accordingly the conveyed stalks--is substantially perpendicular to, and away from, the plane of said flexible belts. The feed rollers comprise an upper pair of parallel rollers the center portions of which are provided with spikes, while the two lateral portions of at least one of said rollers are provided with helical ribs protruding out of the roller surface and surrounding the roller in opposite sense of direction for each lateral portion. Underneath the upper pair of rollers is a second pair symmetrically positioned thereto, which comprises one roller having a spiked surface and one roller having a smooth surface, similarly driven in opposite sense of rotation; the second pair of rollers is positioned close to said rotating shredder.
The shredder, as known to the art, consists of a fast-rotating shaft having a plurality of radial cutter arms pivotally attached to its circumference; each arm is provided at its end with a cutter blade which moves parallel to the shaft axis, and corresponding to the cutter blades at least one stationary cutter blade is positioned in the space between the second pair of rollers and the said movable cutter blades. The shredder is enclosed in a casing which is connected to the suction port of a centrifugal blower.
The equipment operates as follows: each stalk extracted is gripped between the contacting belt stretches and brought to the top of the vehicle frame where it is relinquished and gripped by the two rollers of the upper pair; since the plants enter the gap between the rollers from the two belt conveyors from the two roller ends, they are brought to the central portion by means of the helical ribs and are fed in downward direction into the lower pair of rollers, which feed them straight into the shredder. The shredder comminutes each stalk into small particles which are sucked out of the shredder casing by the said centrifugal blower and delivered into an attached wheeled container. Alternatively the blower may be provided with a rearward directed outlet spout through which the particles are blown into the open and distributed over the area.